Archery is one of the most difficult of all sports due to the demand for consistent accuracy in order to enjoy success in this sport. What makes archery so difficult is that each time the archer shoots an arrow he is faced with the necessity of adjusting several important variables. He must adjust elevation of the arrow to compensate for distance and the horizontal angle for windage. Even if he is able to complete these adjustments successfully, he must repeatedly draw the arrow each time to the same anchor point in order to assure that the adjustments used result in the desired aim. The archer must further make sure that he does not torque the bow up, down, or sideways. All of these variables and others require very significant skills which generally are acquired only through experience. If compensation is not made for all of these variables, then the net result must be that the target will either be missed or the cluster on the target will be off center and inconsistent from one series of shots to another.
Traditionally, the archery bow is fired by the archer sighting along the length of the arrow and directing the arrow in predetermined relationship with respect to the target before releasing the arrow. Various devices have been developed which aid the archer in making the adjustments and aiming, so that the archer does not depend entirely on manual skill and dexterity.
Examples of mechanical aids to the archer are e.g., bubble levels, which have been introduced into or near the sight to tell the archer if the bow is vertical or canted off the vertical. Such tilting of the bow while shooting can cause inconsistencies in the arrow groupings, as well as errors in windage adjustments. Bubble levels are disadvantageous because they require the archer to split his concentration between the target and the levels.
A mechanical means by which an archer can assure that the arrow is drawn to the same spot every time is a device called a clicker. This device is made from a piece of spring steel attached to the bow in front of the arrow rest. The clicker is lifted from the bow and the arrow is placed on the arrow rest. The tension on the clicker is then released, causing the spring steel to rest firmly against the shaft of the arrow. When the arrow is fully drawn the point of the arrow passes the spring steel of the clicker, which causes the metal to impact the bow solidly, creating an audible sound. This sound tells the archer he is at full draw. The advantage of this device is that the archer can be certain that the arrow is drawn and released at the same spot with each shot. This disadvantage of the metal clicker is that shooting prematurely while concentrating on the target causes the feathers or vanes to be torn off the shaft of the arrow. In addition, a device as in U.S. Pat. No. 3,867,920 uses electric current to activate a signal when the arrow is fully drawn. This device utilizes a band of metal on the arrow which completes a current. This device is not suitable for use with the widely used aluminum arrow which is electrically conductive.
There are various types of bow sighting devices which are known to the art. These devices utilize an assortment of methods to make the various compensations discussed herein. Many have one or more sight pointers, which are typically preset for various ranges prior to drawing of the bow. These devices are convenient when target shooting at known ranges. The signt pointer is not readily adjustable for all distances as the range changes and when the bow is drawn. There are devices which are best used for target archery where distances are known, while others are designed for actual hunting where distances are unknown and where the distances change rapidly. Sample patents teaching various devices include U.S. Pat. No. 3,667,444 (1972); U.S. Pat. No. 3,524,440 (1970); U.S. Pat. No. 3,766,656 (1973); U.S. Pat. No. 3,867,920 (1975); U.S. Pat. No. 3,945,127 (1976); and U.S. Pat. No. 3,910,700 (1975).
Because most of the prior art devices depend for their adjustment upon the skill of the archer, there has been need for mechanical sighting means which are convenient to use, are readily attached to the bow, are accurate, can be used with non-conductive and condictive arrows, and do not depend entirely on the skill of the archer for adjustment.